HClO4 is commonly known as Perchloric acid. As the name suggests, this compound is an acid. Generally an acid, is a proton donor, has a pH below 7, neutralizes base and turns blue litmus paper to red. This also means that in a solution (in water) HClO4 produces Hydronium ions (H3O+ ions).

The chemical equation for the dissociation of Perchloric acid (HClO4) in the solution can be written as:

H2SO4 (aq) + H2O ---> H3O+   +   HClO4-        

 **hydronium ions can be represented as H3O+ or simply H+. 

Perchloric acid is classified as a strong acid